Enhanced forward efficiency of Y3Al5O12:Ce3+ phosphor from white light-emitting diodes using blue-pass yellow-reflection filter.

This paper reports a simple approach for the design of blue-excitation-light passing and phosphor-yellow-emission-light reflecting dielectric multilayers to recycle the backward emission of Y(3)Al(5)O(12):Ce(3+) (YAG:Ce) yellow phosphors on top of a blue InGaN light-emitting diode (LED) cup. The insertion of modified quarter-wave films of alternate high- and low-refractive index dielectric films (TiO(2)/SiO(2)) into the interface between a YAG:Ce phosphor layer and glass substrate resulted in 1.64 and 1.95 fold increase in efficiency and luminous efficacy of the forward white emission compared with that of a conventional phosphor on top of a blue LED cup with a lower correlated color temperature (< 4000 K).

[1]  P. Schlotter,et al.  Luminescence conversion of blue light emitting diodes , 1997 .

[2]  Takashi Mukai,et al.  Superbright Green InGaN Single-Quantum-Well-Structure Light-Emitting Diodes , 1995 .

[3]  E. Fred Schubert,et al.  Trapped whispering-gallery optical modes in white light-emitting diode lamps with remote phosphor , 2006 .

[4]  M. Yamada,et al.  Red-Enhanced White-Light-Emitting Diode Using a New Red Phosphor , 2003 .

[5]  E. Schubert,et al.  Analysis of high-power packages for phosphor-based white-light-emitting diodes , 2005 .

[6]  Young Rag Do,et al.  Optical properties of three-band white light emitting diodes , 2003 .

[7]  M. Craford,et al.  Status and Future of High-Power Light-Emitting Diodes for Solid-State Lighting , 2007, Journal of Display Technology.

[8]  Paul S. Martin,et al.  High performance thin-film flip-chip InGaN–GaN light-emitting diodes , 2006 .

[9]  F. Stadler,et al.  Highly efficient all‐nitride phosphor‐converted white light emitting diode , 2005 .

[10]  Shuji Nakamura,et al.  High‐power InGaN single‐quantum‐well‐structure blue and violet light‐emitting diodes , 1995 .

[11]  S. Nakamura,et al.  Candela‐class high‐brightness InGaN/AlGaN double‐heterostructure blue‐light‐emitting diodes , 1994 .

[12]  N. Narendran,et al.  Extracting phosphor‐scattered photons to improve white LED efficiency , 2005 .

[13]  A. Steckl,et al.  A nearly ideal phosphor-converted white light-emitting diode , 2008 .

[14]  Yuichi Sato,et al.  Full-Color Fluorescent Display Devices Using a Near-UV Light-Emitting Diode , 1996 .

[15]  P. Baumeister,et al.  Multilayer mirrors with high reflectance over an extended spectral region. , 1966, Applied optics.

[16]  N. Hirosaki,et al.  Luminescence Properties of a Red Phosphor, CaAlSiN3 : Eu2 + , for White Light-Emitting Diodes , 2006 .